Improvement in telegraph relays and sounders



2 Sheets--Sheet1. 1. B. STEABNS.

Telegraph Relays and Saunders. No.136,876. PatentedMarch18,1873.

AM PHOTU'LITHOGRAPH/C cu m xmsaomvss mocgss) 2 Sheets--S'heet2.

.l. B. STEARNS.

Telegraph Reiays and S0unders.'

NO.136,876, I PatentedMarch18,l873.

An PHOTOiIIHOGRAFHIC 00. N )nfosaonufi'smoczss) UNITED STATES PATENTOEEIoE.

JOSEPH B. STEARNS, OF BOSTON, MASSACHUSETTSo IMPROVEMENT IN TELEGRAPHRELAYS AND SOUNDERS.

Specification forming part of Letters Patent No. 136,876, dated March18, 1873.

CASE A.

To all whom it may concern:

Be it known that I, JOSEPH B. STEARNS, of Boston, in the county ofSuffolk, State of Massachusetts, have invented an Improvement inTelegraph Apparatus, of which the following is a specification:

The nature of this invention consists in a method of preventing theefi'ect of retardation due to static induction on the transmission ofsignals on submarine, subterranean, or long land lines of telegraph, andof obviating the necessity of a fine adjustment in the relay orreceiving instrument, by automatically weakening it during thetransmission of the signal, and at the completion of the stroke of thearmature.

The accompanying drawing, making part of this specification, representsthe various forms in which my invention may be applied to telegraphicpurposes.

In telegraphing through submarine, subterranean, or long land lines oftelegraph, the phenomena technically known as retardation, which iscaused by the static induction of the line, prevents the current, when asignal is transmitted, from arriving at once at its full intensity, ornearly so, as in short lines, but causes it to come feebly at first,gradually increasing until a certain maximum strength is reached, andthen it gradually subsides. Thus, the character of the transmittedsignals is changed during transmission, the long and short signalsforming dots and dashes are not accurately defined, the proper spacingis not preserved, and the signals coalesce and are received in onecontinuous but not uniform signal. This renders telegraphing onsubmarine and long land lines slow, and necessitates a constant and verycareful adjustment in the receiving-relay, in order to get intelligiblesignals. Heretofore, the ordinary method of obviating this difficulty,so as to permit the reception of readable signals, has been the use,upon the relay, ot' a retracting-spring of sufficient power to resistthe current until it has reached acertain strength, which results inshortening the signals, causing what is technically called lightwriting, and necessitates a constant and very delicate adjust ment inthe relay for if the spring of the relay is so strengthened that it isovercome when the strength of the current has reached, say, one-half themaximum at the beginning of the signal, it will, in turn, overcome thecurrent when its strength has diminished to one-half the maximum at itstermination, thus making 7 the received signal much shorter than thetransmitted signal; and in case a dot or short signal is made so quicklyas not to allow the strength of the current to reach this half maximum,the instrument at the receiving end will not be affected, and no signalwill be received; while, on the other hand, it the spring be so weakenedas to lengthen the signal, it will not have sufiicient power to overcomethe efi'ect on the relay of the prolonged partial current due toretardation, and the armature will not be withdrawn during the intervalbetween two successive signals.

If, however, the attractive force of the relay can be weakened after ithas done its work of moving the armature and closing thesounder-circuit, which is the same in efiect as strengthening thespring, a weak spring can be used, so as to permit the reception of along signal, and thus avoid light writing, and at the same time thisweak spring, owing to the weakening of the magnet, will have power toretract the armature at the close of the signal, and sticking will beprevented. I accomplish this automatically by connectingthe relay with ashunt, or by shortcircuiting one of the coils, or in any other analogousmanner weakening the relay by the movement of its armature, in themanner which I will now proceed to describe, and which is shown in thedrawingaccompanying and forming part of this specification.

In Figure l, R represents the relay or receiving magnet of a submarine,subterranean, or long land line; L, the line; S, the soundermagnet; tob, the contact-stops of the relay; 0 d, the contact-stops of thesounder; and m, the shunt, which, as shown in the figure, is connectedwith the relay when contact is made by the sounder-points. In thisapparatus, as soon as the current reaches sufficient strength toovercome the spring, the sounder-circuit is closed, and thecontact-points c and 61 complete a circuit through the shunt, andthereby weaken the current in the relay; but as the current has by thismagnet.

stroke of the armature-lever and follows it on its upstroke, keeps theshunt 'on while the sounder-lever is making the greater part of itsmovement, and allows the terminating-current to become so weak and therelay-armature to get so far from'the poles of the magnet that when theshunt is cut off the relay has not power enough to repeat the signal.

Fig. 3 represents a modification of the apparatus in which the relay isweakened by cutting off or short-circuitin g one helix of the A shuntmay be introduced into the branch circuit, if desired.

Fig. 4 represents a modification in which the relay is composed of twowires, one of which is broken when the sounder-circuit is closed, andthe relay. is thereby weakened. Instead of winding the helices withtwowires, as represented, they may be made one, or each in two or moresections, and be disconnected by closing the sounder-circuit, as before;or the helices may be composed of concentric shells, and one or moreshells be disconnected in like manner. These forms are more particularlyapplicable to quantity magnets and short circuits. v

Fig. 5 shows a modification in which the relay is wound with two wires,as in Fig. 4; but the two are connected for intensity instead of forquantity. When the sounder is open the current from the line goesthrough both wires, one after the other; but when it is closed it goesthrough only one of the wires, and to earth. Instead of making the relayof two wires it may be made of two or more sections or shells, as beforementioned, and one or more of the shells disconnected.

Figs. 6 and 7 represent the manner of applying this invention to a relayor receiving magnet when no local battery or sounder is used. In thisform the closing of the relaypoints shunts one or both of the coils, asmay be found :most convenient; or short-circuits one of the coils byomitting the shunt and connecting, as shown.

Fig. 8 shows an arrangement intended to prevent theeffect of varyingcurrents. In

this plan the shunt is not brought into action while the current isweak, the armature being arrested by the point a in the armc, whichcloses the local circuit at a; but if the current increases for a longeror shorter period the greater pressureat a overcomes the spring d andthe shunt-points are closed at 1), weakening the relay to its,ordinarystandard.

Fig.9 represents a modification of the arran gement shown in Fig. 8, inwhich two shunts are introduced successively. When the; current reachesa certain strength the shunt m is thrown on by the point a, and on thefurther increase in thestrength of the current the shunt m is thrown onat b.

- Fig. 10 is another modification in which the first shunt is thrown onby the sounder, as in Figz'l, and the second shunt is thrown on at b bythe force of the increased current overcoming thespring d.

Fig. 11 shows one method of applying this invention to the duplexinstrumei'it. In this plan the -shunt is thrown across the relay;

from the line screw-cup to the rheostat screwcup.

Fig. 12 shows another method of applying the invention to the duplexinstrument. In

this arrangement the course of the current isdift'erent from that in theother plans. The

arriving current traverses the line-wire of both coils with full force,as shown by the large ar rows in the drawing, giving the magnet acertain strength; but when the shunt is put on by closing the soundercontact-points the course of the current changes, as shown by; the smallarrows. The arriving current then enters and traverses the line-wire ofthe coil R until it arrives at the point i, where it di- 2 vides, oneportion passing with diminished force through the line-wire of coil R,and the other passing through the sounder-points back

